MONDAY, Dec. 4, 2017 (HealthDay News) -- Pairing medication with an ingestible sensor can help clinicians track how often and when patients actually take their prescription drugs, according to a small new investigational study.

The findings come on the heels of the U.S. Food and Drug Administration's decision last month to approve the first digital pill for use with the antipsychotic drug Abilify, often prescribed to treat schizophrenia, bipolar disorder and depression.

The new research involved just 15 patients, all of whom had been prescribed the opioid pain drug oxycodone (OxyContin) after sustaining a fracture.

However, the study participants were given a special configuration of oxycodone. The pain med was packaged together with a so-called "digital pill." This meant that each time a patient took the pain med, they ingested a gelatin capsule that contained the oxycodone as well as a radiofrequency emitter.

The emitter was automatically activated when the capsule was swallowed. It sent signals to a sticky patch placed on the person's abdomen. That, in turn, conveyed basic pill-taking information to an iPod-sized reader.

The system enabled researchers to track how many pills the 15 patients actually took, rather than the number of pills they'd been given.

On average, the patients took just six pills total -- even though they had been provided a supply of 21 pills, according to the report.

"As an investigational tool, the digital pill provides a direct measure of opioid ingestion and changes in medication-taking behavior," senior author Dr. Edward Boyer said in a news release from Brigham and Women's Hospital in Boston.

"This technology may also make it possible for physicians to monitor adherence, identify escalating opioid use patterns that may suggest the development of tolerance or addiction, and intervene for a specific medical condition or patient population," he added.

Boyer is with the medical toxicology division within the hospital's department of emergency medicine.

Boyer and his colleagues published their findings in the December issue of the journal Anesthesia & Analgesia.